CT灌注成像评价颈内动脉重度狭窄患者药物及介入干预的疗效

目的探讨CT灌注成像（CTP）评价颈内动脉狭窄患者药物治疗与支架成形术前后血流动力学变化及其应用价值。方法前瞻性纳入40例经CTA检查并经DSA确诊单侧颈内动脉重度狭窄（患侧狭窄率〉70％，对侧狭窄率〈30％）的患者，同时行CTP。对其中22例DSA检查提示缺血部位有良好代偿、血流无明显延迟的患者（服药组），服用阿司匹林100mg、氯吡格雷75mg、阿托伐他汀20mg。1年后再次行头部CTA及CTP检查。另对18例因无代偿或代偿不够充分，血流有明显延迟的患者行狭窄部位的支架置人术（手术组），术后抗凝3d，继之服用抗血小板聚集及稳定斑块的药物（同服药组）。将两组病例的相对灌注参数值：局部脑血流量（rCBF）、脑血容量（rCBV）、平均通过时间（rMTT）、达峰时间（胛P）进行对比分析（包括入院时初查及1年后复查）。将手术组（包括术前、术后7d、术后1年）的各绝对灌注参数，进行患侧与健侧的对比分析以及3个不同时间点相对应部位绝对灌注参数的动态变化进行分析，并将服药组与手术组术前及术后的卒中事件进行对比分析。结果①服药组服药前及手术组术前各相对灌注参数比较，除rCBF（0．86±0．18、0．42±0．26）、rCBV（1．02±0．03、1．15±0．06）差异有统计学意义（P〈0．05）外，其余参数差异均无统计学意义（P〉0．05）。②服药组服药后1年及手术组术后t年各相对灌注参数比较，除rCBF和rCBV外，其余参数差异均有统计学意义（P〈0．05）。③18例手术组患者，术前患侧rITP、MTr延迟，CBF不同程度降低，与健侧比较，差异有统计学意义，P〈0．05。术后7dCTP成像：CBF明显改善，TTP、MTF仍有延迟。术后1年CTP成像：1ITP、MTr、CBF、CBV患侧与健侧相比差异均无统计学意义，3个时间点绝对参数比较，患侧TTP、MTT、CBF的改变差异有统计学意义（P〈0．05）。④服药组服药期随访1年，新增TIA数2例，治疗前2例TIA患者中有1例好转；手术组18例患者术后随访1年；无新增病例，治疗前16例TIA患者中，有9例好转，前后比较差异有统计学意义（P〈0．05）。结论CTP可以较准确地反映颈内动脉狭窄患者服药治疗和支架成形术前后的血流动力学状况，依据相关参数结合临床及DSA检查结果，对合理选择手术适应证，客观地评价疗效和预后有积极的指导作用。

Efficacy evaluation of CT perfusion imaging for medical and endovascular treatment in patients with internal carotid arterial stenosis

Objective To investigate the CT perfusion （CTP） imaging for evaluation of hemodynamic changes in patients with internal carotid stenosis before and after the medication and stenting. Methods Forty patients with severe unilateral internal carotid stenosis （ipsilateral stenosis 〉 70%, contralateral stenosis 〈30% ） were detected by CT angiography （CTA） and conformed by digital subtraction angiography （ DSA）, CTP imaging was performed at the same time. Twenty-two patients with good vascular compensation at the ischemic sites and with no significant delay in blood flow were treated with medication （aspirin 100 mg, clopidogrel 75 mg and atorvastatin 20 mg daily）. CTA and CTP were performed again after one year. Stenting was performed in the other 18 patients without vascular compensation or inadequate compensation and significantly delayed in blood flow, and then they took anti-platelet aggregation and plaque stable drugs （the same as the medication group）. The relative perfusion parameters including regional cerebral blood flow （rCBF）, regional cerebral blood volume （rCBV）, regional mean transit time （rMTF） , and regional time to peak （rTFP） in both groups （including the examination on admission and reexamination after one year）were compared. All the absolute perfusion parameters of the ipsilateral and contralateral sides in the operation group （ including before the procedure, 7 days and one year after the procedure） were also compared. Results （1）All the relative perfusion parameters before medication and before operation were compared. In addition to rCBF （0.86 ± 0. 18 ; 0.42± 0.26 ） and rCBV （ 1.02 ± 0. 03 ; 1.15 a： 0.06）, there were no significant difference in other parameters （ P 〉 0.05 ）. （2）All the rela- tive perfusion parameters after taking medicine for one year in the medication group and one year after the procedure in the operation group were compared. In addition to rCBF, there were significant differences in other parameters （P 〈 0.05）. （3）TTP and MTT were delayed on the ipsilateral sides before the procedure, and CBF were decreased to various degrees in 18 patients in the operation group, compared to the contralat- eral sides, there were significant difference. Seven days after the procedure, CTP imaging showed that CBF was improved significantly, and TIP and MTT were still delayed. In comparison with the ipsilateral and contralateral sides one year after the procedure in CTP imaging, there were no significant differences among TTP, MTT, CBF, and CBV. The comparative analysis of the absolute parameters at 3 time points were per- formed, and there were significant differences in the changes of TTP, MTF, and CBF on the ipsilateral sides （P 〈 O. 05 ）.（1）After the medication group were followed up for 1 year, there were two new patients with TIA, and one of the two patients improved before the treatment. Eighteen patients in the operation group were followed up for one year after the procedure, and there were no new patients suffered TIA. A- mong the 16 patients with TIA before the procedure, 9 improved, and there were significant differences be- fore and after the procedure （P 〈 0.05）. Conclusion CTP imaging can accurately reflect the medication and hemodynamic conditions of patients with internal carotid stenosis before and after stenting, According to the related parameters in combination with the clinical and DSA results, it has the guiding role for reasona- ble choice of surgical indications and objectively evaluate the efficacy and prognosis.